A power battery of a UAV when working may discharge at a high rate, generating a large amount of heat and leading to a significant temperature rise. In addition, the power battery of the UAV is often includes a plurality of cells connected in series and/or parallel. It is difficult for the heat inside the battery to dissipate. Further, the temperature within the battery is not uniform and the temperature at some locations can be very high, thereby further causing the battery to fade faster, shortening the life span thereof, and influencing safety performance thereof. Therefore, a thermal management device is needed to solve the problems of temperature rise and non-uniform temperature distribution in the cells.
A conventional power battery for UAV is generally made by directly stacking a plurality of cells, then cladding them using a thermal shrinkage gummed paper, and does not have a thermal management device.
At present, an automotive power battery has a thermal management device. For example, Tesla uses a liquid-cooled thermal management device, which includes a cooling pipeline arranged zigzag among the cells and uses a mixture of 50% water and 50% ethylene glycol as a cooling liquid. The cooling liquid flows within the pipeline to take away the heat generated by the battery.
A Volt car made by the General Motors also uses a similar liquid-cooled thermal management device. Metal heat sinks (with thickness of 1 mm) are arranged spaced apart between individual cells, with flow channel grooves engraved on the heat sinks. The cooling liquid may flow within the flow channel grooves and take the heat away.
A LEAF electric vehicle made by Nissan uses a passive battery thermal management device to reduce the amount of heat generated by the battery. For example, electrodes of the battery are optimized to reduce an internal impedance, a thickness of the battery is decreased (an individual cell has a thickness of 7.1 mm) to prevent the heat within the battery from accumulating.
However, a conventional power battery for UAV does not have a thermal management device. The liquid-cooled thermal management device for a conventional vehicle-mounted power battery comprises a cooling pipeline, a cooling liquid, and a management and control system, which are complex. A product cost and a maintenance cost are increased. For example, since the cooling liquid needs to be circulated, a power system needs to be equipped, increasing extra power consumption. Furthermore, the liquid-cooled thermal management device has a large weight and a large volume, increasing the power consumption and limiting an application thereof.
A conventional vehicle-mounted passive battery thermal management device has a high requirement on the battery, limiting the selection of the battery. Moreover, since a thin-body battery is used, whose electrodes have a small thickness, it leads to a poorer performance of magnification, and a higher cost of the whole thermal management device.